[PATCH] OCFS2: The Second Oracle Cluster Filesystem

The OCFS2 file system module.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 232 insertions, 0 deletions

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
new file mode 100644
index 00000000000..d424041b38e
--- /dev/null
+++ b/fs/ocfs2/buffer_head_io.c
@@ -0,0 +1,232 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * io.c
+ *
+ * Buffer cache handling
+ *
+ * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "inode.h"
+#include "journal.h"
+#include "uptodate.h"
+
+#include "buffer_head_io.h"
+
+int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
+		      struct inode *inode)
+{
+	int ret = 0;
+
+	mlog_entry("(bh->b_blocknr = %llu, inode=%p)\n",
+		   (unsigned long long)bh->b_blocknr, inode);
+
+	BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
+	BUG_ON(buffer_jbd(bh));
+
+	/* No need to check for a soft readonly file system here. non
+	 * journalled writes are only ever done on system files which
+	 * can get modified during recovery even if read-only. */
+	if (ocfs2_is_hard_readonly(osb)) {
+		ret = -EROFS;
+		goto out;
+	}
+
+	down(&OCFS2_I(inode)->ip_io_sem);
+
+	lock_buffer(bh);
+	set_buffer_uptodate(bh);
+
+	/* remove from dirty list before I/O. */
+	clear_buffer_dirty(bh);
+
+	get_bh(bh); /* for end_buffer_write_sync() */                   
+	bh->b_end_io = end_buffer_write_sync;
+	submit_bh(WRITE, bh);
+
+	wait_on_buffer(bh);
+
+	if (buffer_uptodate(bh)) {
+		ocfs2_set_buffer_uptodate(inode, bh);
+	} else {
+		/* We don't need to remove the clustered uptodate
+		 * information for this bh as it's not marked locally
+		 * uptodate. */
+		ret = -EIO;
+		brelse(bh);
+	}
+
+	up(&OCFS2_I(inode)->ip_io_sem);
+out:
+	mlog_exit(ret);
+	return ret;
+}
+
+int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
+		      struct buffer_head *bhs[], int flags,
+		      struct inode *inode)
+{
+	int status = 0;
+	struct super_block *sb;
+	int i, ignore_cache = 0;
+	struct buffer_head *bh;
+
+	mlog_entry("(block=(%"MLFu64"), nr=(%d), flags=%d, inode=%p)\n",
+		   block, nr, flags, inode);
+
+	if (osb == NULL || osb->sb == NULL || bhs == NULL) {
+		status = -EINVAL;
+		mlog_errno(status);
+		goto bail;
+	}
+
+	if (nr < 0) {
+		mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
+		status = -EINVAL;
+		mlog_errno(status);
+		goto bail;
+	}
+
+	if (nr == 0) {
+		mlog(ML_BH_IO, "No buffers will be read!\n");
+		status = 0;
+		goto bail;
+	}
+
+	sb = osb->sb;
+
+	if (flags & OCFS2_BH_CACHED && !inode)
+		flags &= ~OCFS2_BH_CACHED;
+
+	if (inode)
+		down(&OCFS2_I(inode)->ip_io_sem);
+	for (i = 0 ; i < nr ; i++) {
+		if (bhs[i] == NULL) {
+			bhs[i] = sb_getblk(sb, block++);
+			if (bhs[i] == NULL) {
+				if (inode)
+					up(&OCFS2_I(inode)->ip_io_sem);
+				status = -EIO;
+				mlog_errno(status);
+				goto bail;
+			}
+		}
+		bh = bhs[i];
+		ignore_cache = 0;
+
+		if (flags & OCFS2_BH_CACHED &&
+		    !ocfs2_buffer_uptodate(inode, bh)) {
+			mlog(ML_UPTODATE,
+			     "bh (%llu), inode %"MLFu64" not uptodate\n",
+			     (unsigned long long)bh->b_blocknr,
+			     OCFS2_I(inode)->ip_blkno);
+			ignore_cache = 1;
+		}
+
+		/* XXX: Can we ever get this and *not* have the cached
+		 * flag set? */
+		if (buffer_jbd(bh)) {
+			if (!(flags & OCFS2_BH_CACHED) || ignore_cache)
+				mlog(ML_BH_IO, "trying to sync read a jbd "
+					       "managed bh (blocknr = %llu)\n",
+				     (unsigned long long)bh->b_blocknr);
+			continue;
+		}
+
+		if (!(flags & OCFS2_BH_CACHED) || ignore_cache) {
+			if (buffer_dirty(bh)) {
+				/* This should probably be a BUG, or
+				 * at least return an error. */
+				mlog(ML_BH_IO, "asking me to sync read a dirty "
+					       "buffer! (blocknr = %llu)\n",
+				     (unsigned long long)bh->b_blocknr);
+				continue;
+			}
+
+			lock_buffer(bh);
+			if (buffer_jbd(bh)) {
+#ifdef CATCH_BH_JBD_RACES
+				mlog(ML_ERROR, "block %llu had the JBD bit set "
+					       "while I was in lock_buffer!",
+				     (unsigned long long)bh->b_blocknr);
+				BUG();
+#else
+				unlock_buffer(bh);
+				continue;
+#endif
+			}
+			clear_buffer_uptodate(bh);
+			get_bh(bh); /* for end_buffer_read_sync() */
+			bh->b_end_io = end_buffer_read_sync;
+			if (flags & OCFS2_BH_READAHEAD)
+				submit_bh(READA, bh);
+			else
+				submit_bh(READ, bh);
+			continue;
+		}
+	}
+
+	status = 0;
+
+	for (i = (nr - 1); i >= 0; i--) {
+		bh = bhs[i];
+
+		/* We know this can't have changed as we hold the
+		 * inode sem. Avoid doing any work on the bh if the
+		 * journal has it. */
+		if (!buffer_jbd(bh))
+			wait_on_buffer(bh);
+
+		if (!buffer_uptodate(bh)) {
+			/* Status won't be cleared from here on out,
+			 * so we can safely record this and loop back
+			 * to cleanup the other buffers. Don't need to
+			 * remove the clustered uptodate information
+			 * for this bh as it's not marked locally
+			 * uptodate. */
+			status = -EIO;
+			brelse(bh);
+			bhs[i] = NULL;
+			continue;
+		}
+
+		if (inode)
+			ocfs2_set_buffer_uptodate(inode, bh);
+	}
+	if (inode)
+		up(&OCFS2_I(inode)->ip_io_sem);
+
+	mlog(ML_BH_IO, "block=(%"MLFu64"), nr=(%d), cached=%s\n", block, nr,
+	     (!(flags & OCFS2_BH_CACHED) || ignore_cache) ? "no" : "yes");
+
+bail:
+
+	mlog_exit(status);
+	return status;
+}